virsh: Try to keep printed XML pretty with change-media
virsh: Try to keep printed XML pretty with change-media

When adding a new media with change-media and --print-xml, let's try
making it more readable and nice.

Before:
<disk type="file" device="cdrom">
...
      <target dev="hdb" bus="ide"/>
      <address type="drive" controller="0" bus="0" target="0" unit="1"/>
    <source file="/tmp/a.iso"/></disk>

After:
<disk type="file" device="cdrom">
...
      <source file="/tmp/a.iso"/>
      <target dev="hdb" bus="ide"/>
      <address type="drive" controller="0" bus="0" target="0" unit="1"/>
    </disk>

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1219719

Signed-off-by: Martin Kletzander <e82f23e74d43760279ebcc505dac4ae70d5627d0@redhat.com>

nertpinx/libvirt,nertpinx/libvirt,libvirt/libvirt,nertpinx/libvirt,libvirt/libvirt,crobinso/libvirt,zippy2/libvirt,taget/libvirt,jfehlig/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,rlaager/libvirt,crobinso/libvirt,datto/libvirt,fabianfreyer/libvirt,eskultety/libvirt,taget/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,zippy2/libvirt,olafhering/libvirt,andreabolognani/libvirt,eskultety/libvirt,VenkatDatta/libvirt,datto/libvirt,datto/libvirt,jardasgit/libvirt,taget/libvirt,rlaager/libvirt,jfehlig/libvirt,datto/libvirt,VenkatDatta/libvirt,taget/libvirt,andreabolognani/libvirt,taget/libvirt,jardasgit/libvirt,eskultety/libvirt,jardasgit/libvirt,olafhering/libvirt,andreabolognani/libvirt,eskultety/libvirt,rlaager/libvirt,andreabolognani/libvirt,libvirt/libvirt,jardasgit/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,zippy2/libvirt,crobinso/libvirt,nertpinx/libvirt,crobinso/libvirt,olafhering/libvirt,nertpinx/libvirt,zippy2/libvirt,libvirt/libvirt,rlaager/libvirt,eskultety/libvirt,fabianfreyer/libvirt,datto/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,olafhering/libvirt,jardasgit/libvirt,rlaager/libvirt,VenkatDatta/libvirt